Electric attachment plug



May 19, 1925.

- 1,538,057 R. v. OWEN ELECTRIC ATTACHMENT PLUG Filed Sept. 20, 1920 //vv /v7'0R. fizz amend Vfiwen.

Patented May 19, 1925.

UNITED STATES PATENT OFFICE.

RAYMOND V. OWEN, OF ST. LOUIS, MISSOURI, ASSIGNOR TO ST. LOUIS BRASS MANU- FACTURING COMPANY, OF ST. LOUIS, MISSOURI, A CORPORATION OF MISSOURI.

ELECTRIC ATTACHMENT IELUG.

Application filed September 20, 1920. Serial No. 411,376.

T 0 all whom it may concern:

Be it known that I, RAYMOND V. OWEN, a citizen of the United States, residing at St. Louis, Missouri, have invented a certain new and useful Improvement in Electric Attachment Plugs, of which the following is a full, clear, and exact description, such as will enable others skilled in the art to which it appertains to make and usethe same, reference being had to the accompanying drawings, forming part of this specification.

My invention relates generally to devices utilized for the distribution of electric cur rent and more particularly to an electric attachment plug that is connected to the ends of a pair'of flexibleconductors and which plug is adapted to be screwed into a socket.

The principal object of my invention is to provide a relatively simple and efficient electric attachment plug, and to construct the same so that the contact members are firmly secured to the body of the plug without the use of the usual screws, rivets, or like fastening elements.

Further objects of my invention are, to provide a plug having relatively few parts; to provide a construction which can be manufactured at relatively low cost; and to provide a plug wherein the terminals of the wires or current carrying 'members are connected to the Contact members of the plug without the use of extraneous fastening devices.

With the foregoing and other objects in View, my invention consists in certain novel features of construction and arrangement of parts, hereinafter more fully described and claimed and illustrated in the accompanying drawing, which is a half elevational viewailid half longitudinal section through the p ug.

Referring by numerals to the accompanying drawing, 1 designates the mainbody of the plug, the same being preferably constructed from porcelain, hard rubber, or other suitable insulating material. One end of thisplug body terminates in an annular flange having a knurled edge 2 whereby the plug may be engaged when screwed into a socket and spaced a short distance from this flange and near the center of the body 1 is an annular flange 3 from which projects a shank 4. This shank is integral with the body of the plug and its periphery has formed thereon a thread of the proper pitch to engage in the'ordinary socket. Projecting outwardly from the end of this shank is a nipple 5, the periphery of which is formed with at least two full threads.

Extending axially through the body of the plug, the shank 4, and nipple 5 is a bore or passageway 6 and leading therefrom through the outer end portion of the shank 4 is a branch passageway or opening 7 The outer end of this branch passageway or opening communicates with the thread on the periphery of the shank at the outer end of the latter.

A shell 8 of relatively thin metal such as brass or copper is secured onto the threaded periphery of the shank 4, said shell being provided with a complementary thread which engages the thread on said shank and the outer end of said shell is provided with a narrow annular flange whichbears directly against the shoulder between the shank 4 and nipple 5.

A screw-cap 9 is seated upon and wholly encloses the nipple 5, said cap being provided with a thread which is complementary to the thread on said nipple. Conductors 10 and 10' of the usual type extend through the axially disposed bore or passageway 6 and the exposed terminal portion of one of these conductors, for instance, the one designated by the numeral 10, is bent downwardly over the side of nipple 5 where it is securely engaged and clamped by the cap 9 when the latter is screwed onto said nipple. Thus a firm and substantial electrical contact is provided between one of the conductors and the cap 9 and to retain the latter in position upon the nipple, its lower edge is pressed into an annular groove at the lower or inner end of said nipple as designated by the numeral 12. The end of conductor 10 is extended through the branch passageway 7 and the exposed terminal portion of said conductor is bent down against the periphery of the shank 4 and when'the shell 8 is screwed onto said shank, said exposed end is directly engaged by said shell and pressed against said shank, thereby providing a perfect electrical contact and clamping the end of the conductor so that it cannot accidentally be withdrawn.

To retain the shell 8 on the shank 4, its

lower or inner edge is pressed into an annular groove that is formed in the shank adacent to flange 3, as designated by the numeral 11.

Usually the current carrying members of the conductors 10 and 11 are made up of a number of strands of very fine w1re and in view of this fact it"will be apparent that the casing 8 and cap 9 will readily pass over the plug 4 and nipple 5 and bend the strands of wire securely in place and at the same time forming a perfect electrical contact and retaining the parts in assembled relation.

While I have shown my invention applied to a plug that is adapted to be inserted in a socket I do not desire to be understood as restricting my invention to this particularuse, for it is obvious that practically the same construction may be advantageously applied to a socket or in fact any electrical device where current carrying wires are connected to contact members.

It will be readily understood that minor changes in the size, form andconstruction of the various parts of my improved electric attachment plug can be made and substituted for those herein shown and described, without departing from the spirit of my invention, the scope of which isset forth in the appended claim.

I claim as my invention An electrical attachment plug comprising a body portion channeled through its center V projection on the 'end of the body portion and screw-threaded to engage the screw threads on the periphery of the body portion, secured to the said body portion; a second shell to cover the projection and screwthreaded to engage thescrew threads on the said projection, substantially as shown and described. v

In testimony whereof I hereunto afiix my signature this 17th day of September, 1920.

R, V. OWEN; 

